Editor's Note:The lead author of the following Clinical Observation was one of a dozen Associates of the American College of Physicians selected to present a clinical vignette at the 2004 Annual Session in Philadelphia. We are proud to present this case report through a special arrangement with the Council of Associates of the College.

TO THE EDITOR:

Background: Thiamine deficiency is prevalent among nutritionally deficient persons and typically manifests as Wernicke encephalopathy or beriberi (1). In the published literature, a primary syndrome consisting of gastrointestinal symptoms and signs has not been previously attributed to thiamine deficiency. The following report illustrates 2 cases of gastrointestinal symptoms and lactic acidosis that were probably related to thiamine deficiency.